The only brushless systems I've owned are all Hobbywing <div>
</div><div>1st was a ezrun 35a and 4300kv finned motor. Was plenty fast in my tt01e and lasted a long time. Then I decided to exceed the limits clearly stated in the manual. I put a 3s pack with the 9t motor. Still wasn't enough to kill it so it but it did get hot. So I increased the gearing as high as it can go in a tt01e (i thing 5.5fdr) and drove it for a month then it died. Talk about a tough system to kill!</div><div>
</div><div>After that I bought a ezrun 60a and 4000kv (non finned real 540) motor. I put it in my Tamiya TB03 first. On 3s it hit 50mph and gets a little warm (can touch for 10 seconds after 10 minutes of driving). On 2s it wouldn't even get warm. And it was geared 6.5fdr. Perfect system for the tb03.</div><div>
</div><div>I then purchased a Tamiya DF02 and bought it the same motor and esc as the tb03. It ran hotter but still in the safe zone and I even used 3s which isn't recommended with the 4000kv in an offroad vehicle and it was alright. I beat the snot out of the df02 then sold it on ebay in non working order for more than I bought it for. </div><div>
</div><div>I kept the motor/esc from the df02 and put them in a hsp 1/10 buggy. On 2s it got pretty warm. I put 3s on it as at the time my 2s stuffed up and drove it for a month like that. The capacitors had been ripped off and the fan didn't work. It ran for a month like that, thermalling every 10 minutes then decided to die. The motor still works but its not as smooth as I remember.</div><div>
</div><div>I took the system from the tb03 and put it in a hsp 1/10 touring car. On  2s it gets hotter than the tb03 on 3s and the hsp has lower gearing????</div><div>On 3s it will thermal the esc in 10 minutes (no fan) So I usually drive it for 5 minutes then let it cool. Just to be safe while a new fan comes in the mail. Mind you its 35 degrees celcius here so I can't blame the electronics</div><div>
</div><div>I have a ripper 2000kv motor and 150a xerun esc in my thunder tiger mt4. The ripper decided to one day just stop working so I replaced it with a xerun  hw 2200kv 4274sd sensored motor. My MT4 does about 42mph on 4s now and has more power than I need. And it runs very cool on asphalt and a bit warm on grass after 15 minutes but nothing out of the safety zone</div>